1. Field of the Invention
The present invention relates to a cogeneration system for generating power and heat to be supplied to a plurality of consuming apparatuses (various household electric apparatuses and hot water supplying apparatuses, for example, at general household) consuming power and/or heat in order to operate these consuming apparatuses, an operation controller and operation program for a cogeneration facility.
A cogeneration system is provided with a generator having a fuel cell, a gas turbine or like prime mover as a driving source. The generated power is used at a place of demand (e.g. general household) together with power supplied, for example, from a power supplying company and the generated heat is also utilized at this place of demand, thereby trying to obtain an energy-saving effect.
However, the scale of demand for power and heat at general household is characterized by its considerably large range of variation although being small as compared to factories and commercial facilities. Thus, a problem has been pointed out that a serviceability ratio (i.e., a ratio of operating hours in a day) and a load ratio (i.e., ratio of load to the rated output) are limited and a sufficient energy-saving effect cannot be obtained even if the cogeneration system is introduced to the household.
There has been proposed a method for determining operating conditions of the cogeneration system and the consuming apparatuses from information on the power and heat generating state of the cogeneration system and information on the operation schedules of the consuming apparatuses and controlling the operations of the cogeneration system and the consuming apparatuses based on the respective operating conditions in order to solve the above problem and exhibit the merit of introducing a cogeneration facility (see for example, Japanese Unexamined Patent Publication No. 2003-129904).
FIG. 13 shows a known cogeneration system disclosed in the above publication. This system includes a cogeneration facility CS provided with a fuel cell 101 as a power generator, a hot-water storing tank 102 and a control system 110, a group H of various consuming apparatuses consuming power and/or heat, and energy supply sources such as power, gas and water. In the cogeneration facility CS, power is generated in the fuel cell 101 using the supplied gas or hot water is produced by being heated by the waste heat of the fuel cell 101 and stored in the hot-water storing tank 102, and the control system 110 controls the entire system or carries out a control for utilizing the generated power, hot water (heat). The consuming apparatus group H includes consuming apparatuses 104a, 104b such as a washing/drying machine and a dish washer consuming power and heat, a consuming apparatus 105 such as a hot water tap consuming only heat (hot water), a consuming apparatus 106 such as an electric light consuming only power, a consuming apparatus 108 such as a gas cooking stove consuming only gas, and a consuming apparatus 107 such as a water tap consuming only water. The consuming apparatuses 104a, 104b, 105, 106 are provided with controllers 104ac, 104bc, 105c, 106c for the operation control such as the start and end of the operation and the setting of an operation mode.
On the other hand, the control system 110 is provided with a state information receiver 111 for receiving information on the generating states of power and heat in the cogeneration facility CS; a schedule information receiver 112 for receiving information on schedules set by a user concerning the operations of the consuming apparatuses 104a, 104b, 105, 106; an operating condition determiner 113 for determining operating conditions of these consuming apparatuses and the fuel cell 101; a fuel cell controller 114 and a consuming apparatus controller 115 for respectively controlling the fuel cell 101 and the consuming apparatuses 104a, 104b, 105, 106 under the determined conditions, a consumption amount measurer 116 for measuring a consumption amount of the supplied power or the like, and a consumption amount output device 117.
In the cogeneration system thus constructed, the control system 110 can conduct a bilateral communication (indicated by broken-line arrows in FIG. 13) concerning the information on the operation schedules of the consuming apparatuses 104a, 104b, 105, 106 (operation scheduled periods, consumption amount information of power or heat as the form of energy to be consumed) and the generating state information of the power and heat in the cogeneration facility CS. Using generation information on the output states of the cogeneration facility CS at present (or in the future) such as a power output, a heat output, a stored power amount and a stored heat amount, and the operation schedule information on the operation periods during which the consuming apparatuses 104a, 104b, 105, 106 are operated or the consumption amount of power or heat at that time, the control system 110 determines the operating conditions of the cogeneration facility CS and the consuming apparatuses 104a, 104b, 105, 106 as follows.
First, the state information receiver 111 receives information on a present (or future) power output of the fuel cell 101 and the temperature of the hot water discharged from the hot water storing tank 102 from sensors (not shown) of the fuel cell 101 and the hot water storing tank 102. The schedule information receiver 112 receives the information on the operation schedules of the respective consuming apparatuses 104a, 104b, 105, 106, i.e., operation permissible time periods and power consumption amounts and heat consumption amounts based on the operation permissible time periods, from the respective controllers 104ac, 104bc, 105c, 106c. The operating condition determiner 113 increases a power load ratio of the fuel cell 101 within the operation permissible time periods of the respective consuming apparatuses 104a, 104b, 105, 106 received by the schedule information receiver 112, and determines the operating conditions of the respective consuming apparatuses 104a, 104b, 105, 106 and the fuel cell 101 so that the hot water stored in the hot water storing tank 102 can be efficiently consumed. The fuel cell controller 114 automatically operates the fuel cell 101 in accordance with the operating condition determined as above, and the consuming apparatus controller 115 controls the operations of the respective consuming apparatuses 104a, 104b, 105, 106 determined as above by the bilateral communication with the controllers 104ac, 104bc, 105c, 106c of the respective consuming apparatuses.
However, the cogeneration system of the above publication is said to be a system which can be built on the premise that all the consuming apparatuses and the cogeneration facility are connected with a network and the bilateral communication can be conducted via the network concerning the operation schedule information of the consuming apparatuses and the generating state information of the power and heat of the cogeneration facility. Accordingly, if both the consuming apparatuses provided with a the network connecting function and those provided with no such function exist in the cogeneration system, there is a problem that the merit of introducing the cogeneration system cannot be sufficiently exhibited.
Specifically, for so-called white household apparatuses such as washing machines and refrigerators, network white household apparatuses provided with a network connecting function are being commercialized. However, such white household apparatuses are still limited only to some types, and those provided with no network connecting function are a mainstream. Further, since the repurchase cycle of 10 years or longer is not seldom for the white household apparatuses, a state where some of the consuming apparatuses in the cogeneration system are provided with the network connecting function and the others are not is expected to continue for the time being.
In the case that there are consuming apparatuses provided with no network connecting function, the operation excluding such consuming apparatuses is obliged to be performed in the prior art system of the above publication and the fuel cell is controlled under the operating condition determined in the state different from an actual power or heat consumption amount. Generally, the fuel cell takes time to start stably supplying power after the activation from a stopped state because the temperature of a modifier needs to be increased. Thus, it is essential to determine the time at which the fuel cell is activated in accordance with a load expected for all the consuming apparatuses including those not connected with the network so that the fuel cell can stably supply power in conformity with the time at which the consuming apparatuses start consuming power.